The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 19, 1989
Filed:
Nov. 23, 1987
James J Dunn, St. Charles, IL (US);
Chicago Metallic Corporation, Chicago, IL (US);
Abstract
A grid system for suspending a ceiling formed of drywall includes main runners which are interconnected by splice connections having an arrangement for controlling bending to relieve thermal expansion and has cross members formed of channels which are connected to the main runner by a connection having an arrangement for relieving thermal expansion. The splice connection includes a portion of the bead of the main runner being removed to provide bending lines spaced inward from the edge of the web so that bending will occur at two spaced positions at the splice connection to relieve thermal expansion caused by a fire. The connection between the channel cross members and the main runners includes flanges of each of the cross members having a first notch separated from a second notch by a shear tab, the connection is formed by the edge of the aperture in the web of the main runner being received in the first notch and the shear tab being broken off or removed in response to forces of thermal expansion caused by a fire.